Indirect caries-preventive effect of silver diamine fluoride on adjacent dental substrate: A single-section demineralization study.

This study assessed the indirect effect of 38% silver diamine fluoride (SDF) on demineralization of adjacent untreated sound and pre-demineralized enamel and dentine using a single-section model for digital transverse microradiography (TMR-D). Forty-eight bovine dentine single sections were demineralized, stratified (n = 12) according to integrated mineral loss (ΔZ), and treated with SDF or deionized water (DIW). Each "treated dentine" section was attached between untreated sound and pre-demineralized enamel or dentine and then subjected to demineralization. ΔZ and lesion depths (LD) of all specimens at baseline, 24 and 48 h demineralization, and after treatment of "treated dentine" were quantified using TMR-D. Fluoride in the demineralization solution of SDF clusters was determined using an ion-selective electrode. ΔZ and LD of sound and ΔZ of pre-demineralized enamel adjacent to SDF-treated dentine did not increase over time. All untreated dentine demineralized significantly; however, ΔZ of sound dentine adjacent to SDF-treated specimen was still significantly lower than control. SDF-treated dentine remineralized and released fluoride even after 48 h. Consistent with clinical findings, when applied only to demineralized teeth in this chemical model, 38% SDF completely inhibited demineralization in adjacent untreated sound enamel. Demineralization prevention was observed to a lesser extent in adjacent pre-demineralized enamel but not in dentine.